Social media technologies are described as an ensemble IS artefact composed of technical, informational and relational subsystems that interact distinctly according to the context of use. With an emphasis on these dimensions, we build a conceptual framework to examine the influence of user affect and passion for an activity on social media networks, specifically Facebook and Twitter. The research model is based on Affective Events Theory and tested using the responses of 328 attendees of a National Association for Stock Car Auto Racing (NASCAR) event. The results indicate that excitement may not be sufficient to motivate content creation and sharing activities in social media. However, in the context of a meaningful event, excitement interacts with user passion to facilitate social media use. One strategic insight is the knowledge that user (or customer) passion is a condition favorable for social media engagement, representing a lucrative opportunity for organizations to meaningfully engage with consumers.